Urn system and beverage pump



April 16, 1963 P. MATTY URN SYSTEM AND BEVERAGE PUMP Filed May 2, 1960 4 Sheets-Sheet 1 COOL/MIT ENTRY COOLA/VT T0 36 24- 38 r INVENTOR Pete Ma/fy ATTORNEYS A ril 16, 1963 P. MATTY URN SYSTEM AND BEVERAGE PUMP 4 Sheets-Sheet 2 Filed May 2, 1960 INVENTOR Pele Mai/y CC. a a 4 ATTORNEYS.

April 16, 1963 MATTY URN SYSTEM AND BEVERAGE PUMP 4 Sheets-Sheet 3 Filed May 2, 1960 INVENTOR Pele Mal/y ATTORNEY Sf April 16, 1963 P. MATTY URN SYSTEM AND BEVERAGE PUMP 4 Sheets-Sheet 4 Filed May 2, 1960 wry llllllllll INVENTOR Pefe Maffy 12 W, 5. W

ATTORNEYS,

United States Patent 3,085,880 URN SYSTEM AND BEVERAGE PUMP Pete Matty, R0. Box 73, Middletown, Va. Filed May 2, 1960, Ser. No. 26,310 19 Claims. (Cl. 99-71) This invention relates generally to the production of large quantities of hot beverage, particularly coffee.

Applicants issued United States Letters Patent 2,895,403 discloses a beverage pump similar in certain respects to that of the present invention.

A primary object of this invention is to provide in a novel urn system an improved beverage pump including head cooling and lubrication cooling means which permit the make-up water to be readily and expeditiously circulated and tends to prevent vapor locks due to the formation of steam, the invention being particularly adapted for incorporation in single as well as multiple commercial urn-incorporating systems wherein the make-up water is habitually kept at boiling temperature regardless of whether or not thermostatic control is available, unless business is slow.

At this point it is to be noted that approximately 90% of todays commercial coffee urns lack thermostatic makeup Water control and have instead gas control valves with two settings, one marked high and the other low. At high setting the make-up water boils and at low setting the water is at about 180 F. These valves are usually lefit on high or boiling setting unless business is slow and the same is the case with the other of the urns that do have thermostatic Intake-up Water temperature control.

A further object of the invention is to provide safety means especially adapted for use with the novel pump of the system and which facilitates the change over from one urn to another in a dual urn system.

A still further object of the invention is to provide a novel nozzle assembly including changeable orifice means to afford means whereby different strengths of brew may be obtained and which insures circulation and steeping contact between the make-up water and the grounds from which the brew is obtained.

And yet another object of the invention is to provide a novel disposable ground-bag assembly which eliminates maintenance of permanent-type ground-bags and eliminates possible disfiavoring of the brew due to improper maintenance.

A further object of the invention is to provide a novel urn system and pump including unique and desirable features all lending to ready and eflicient brewing of coffee with a substantially uniform strength which can be readily changed, and which is practical and satisfactory for the purpose intended.

Other objects and the nature and advantages of the invention will be apparent from the following description taken in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a front elevation of a dual urn system illustrating the invention, substantially diagrammatic, portions being broken away and shown in section for purposes of clarity;

FIGURE 2 is a top plan view of FIGURE 1 with portions broken away, showing by means of phantom lines how the circulated make-up water for oofiee may be switched from one urn and then .to the other in order to make urn of coffee;

FIGURE 3 is an enlarged vertical section taken substantially on line 33 of FIGURE 1 and showing details of the novel pump of the urn system;

FIGURE 4 is a vertical section taken substantially on line 44 of FIGURE 2;

3,085,880 Patented Apr. 16, 1963 FIGURE 5 is a vertical section taken on line 5-5 of FIGURE 3;

FIGURE 6 is a vertical section taken substantially on line 6-6 of FIGURE 3, showing the cooling fluid chamher in the impellor-chamber head;

FIGURE 7 is a vertical section on line 77 of FIG- URE 3, showing details of the impe'llor-chamber of the P p;

FIGURE 8 is an exploded perspective view of the impellor chamber head of the pump;

FIGURE 9 is an enlarged perspective view of the disposable ground-bag and support basket-screen used in the riser of the urns;

FIGURE 10 is an enlarged side elevation of the novel circulating, replaceable-orifice nozzle of :the invention;

FIGURE 11 is a section taken on line 11-11 of FIG- URE 10 showing the tangential inlet of the nozzle to illustrate how a circulating discharge of make-up water is obtained;

FIGURE 12 is a vertical section of the nozzle taken on line 12-42 of FIGURE 11 and illustrating how the interchangeable orifices are mounted in the nozzle;

FIGURE 13 is a perspective view of an orifice element used in the nozzle of the system;

FIGURE 14 is an enlarged vertical section taken on line 1414 of FIGURE 1 and illustrating the rotatable union which permits the discharge nozzle to be selectively disposed over the urns and showing the operating meansfor a field-control switch for the operating motor of pump of the system; and

FIGURE 15 is a horizontal section taken substantially on line 15-15 of FIGURE 1 showing the microsWi-tch incorporated in the motor-field circuit of the system and illustrating the angul arly disposed switch activating abutments for closing the motor-field only when the discharge nozzle is in centered, overlying relation to tone of the urns.

Referring to the drawings in detail, and first considering FIGURE 1, a dual urn system is indicated generally at 10 and includes similar adjacent urns 12 land 14 which are generally conventional and includes an inner beverage chamber 16, an outer jacket-form make-up water chan ber 18, each subject to being heated by a suitable burner 20. The chambers 18 each communicate with an outlet I spigot 22 and a fluid line 24 connected tothe inlet of a fluid pump indicated generally at 26 which includes an outlet connected to a fluid line 28. Fluid line 28 in turn is connected to a safety, union switch assembly indicated generally at 30 which in turn permits make-up water to be directed to a circulating discharge nozzle indicated generally at 32 which is directed into the upper end of one or the other of the urns 12 or 14 and discharges water into a novel strainer assembly indicated generally at 34.

The urns 12 and 14 include a convention, vertically disposed transparent visual gage 36 and beverage tap 38. Although a dual urn system will be described in detail, it will be appreciated by those skilled in the art that the novel pump, disposable bag and circulating nozzle may be used in a single urn installation.

The novel pump assembly 26 will draw make-up water from the chamber 18 which is maintained at almost the boiling point of water and due to the swirling, steeping action of the make-up water, afiorded by the nozzle assembly 32, a suitable beverage will be afforded by passage of the water only once through the coffee grounds in assembly 34. Since the water does not have to be passed through the grounds more than once, an entire urn of coflee may be made up more rapidly than previously possible. Additionally, the coifee brewed by a single passage of make-up water has been found to be uniform in quality and ex trer'nely palatable, and distasteful oils and brackish taste 3 resulting from re-circulation of the brewed coffee is eliminated.

The spigot 22 is connected by a line 46 to a T 42 connected by nipples 44 to the make-up water chambers 18 which serve to maintain the coffee chambers 16, and the brewed coffee therein, a predetermined temperature.

The urns 12 and 14 each include an upwardly extending annular flange 46 forming an annular ledge 48 which will removably support a cylinder riser i.e. sleeve 50 which will be replaced by a conventional lid 52' after the assembly 34 is removed, i.e. the urn of coffee is brewed. Received within the riser 50 is a cylindrical, open topped screen 52 of a suitable foraminous material, which is also supported on the ledge 48 of the urn. The screen 52 includes a transverse, partially solid bottom 54 which comprises a downwardly directed drainage opening 56 which directs the steeped brewed coffee toward one side of chamber 16 which causes the circulatory clockwise movement of the brewed coffee as it is being prepared. The screen 52 will support therein a paper-product, disposable porous bag 58 which will be wrapped over the upper edge of the screen 52 as indicated at 60. The bag can be of a relatively fragile character and comparatively economical to manufacture. The screen 52 and bottom 54 will support the porous bag 58 during the brewing operation.

Referring to FIGURES l, 2 and 13, it will be noted that the nozzle assembly 32 includes an inverted L-shaped pipe 62 which has its lower end journaled in the safety-union switch assembly 38, the upper end being received and sealed in the tubular end 64 of the nozzle body 66. The nozzle body 66 has a circular inner chamber 68 and the tubular end 64 of the body communicates tangentially with the chamber 68 to cause make-up water to move in a circular path in the chamber 68, as indicated by the direction arrows of FIGURE 11, to have a swirling, steeping action through the grounds G of FIGURE 1. The nozzle body 66 is threaded at 70 at its lower end and receives thereon a clamp nut 72 having an inwardly directed clamp flange 74. Received between the flange 74 and the lower edge 76 of body 66 is an annular orificedisc 78 having an annular lip 80 and an orifice 82. Several discs 78 with different sized orifices 82 will be available and the proper orifice size is determined in relation to the liquid output of the pump assembly 26 and the period of steeping to which the grounds of coffee are subjected. The orifice 82 diameters will usually range from to /2". The nozzle 66 will, as earlier noted, come equipped with a plurality of different orifice discs 78 having graduated outlet apertures or orifices 82 whereby the strength of the brew may be varied, i.e. the grounds will be subjected to make-up water a greater or shorter period of time.

The pump assembly 26 is shown in FIGURES 1 and 2 as being disposed exteriorally of the urns 12 and 14, however, this assembly may be disposed beneath one of the urns in order to conserve space. The pump of applicants issued patent includes features facilitating disassembly and cleaning. However, since a liquid substantially at 212 degrees F. is pumped, if the impellor chamber or conduits should contain too much steam, a vapor lock would occur and no liquid would be circulated. Additionally, since the make-up water is substantially at a boiling temperature, the pump parts would become very hot, thus subjecting various bearings to severe conditions and requiring special seals and lubricants.

The pump assembly 26 includes all the desirable features of the pump of US. Patent 2,895,403 and also includes a novel cooling system for both the irnpellor chamber and lubricant for the drive shaft of the impellor. The assembly 26 includes a suitably rated motor 84 connected by leads 86, 88 to a suitable source of potential. The lead 88 includes a control switch 90 and a suitable timer 92 controlling the running time of the pump 26 and thus determining the amount of make-up water pumped into the urns.

Also connected in the line 88 is a safety control switch 94 indicated diagrammatically in FIGURE 1. The switch 94 will be closed only when the noZZle assembly 32 is located over the center of either the urn 12 or 14 as shown in FIGURES 2, l4 and 15 as will subsequently be described in detail. The switch 94 will control current to the field coil of motor 84 and thus during intermediate positions of the nozzle assembly 32, see FIGURE 2, the motor 84 and thus the pump 96 of the assembly 26 cannot be operated.

Considering FIGURES l, 2, 14 and 15, the L-shaped pipe 62 will include on its lower leg an annular collar 98 which receives thereon an internally threaded sleeve 100. The sleeve 100 receives the upper threaded end 102 of a nipple 104 which includes an intermediate annular shoulder 186 upon which is disposed a sealing washer 188 of Teflon or any other suitable material, the washer sealingly engaging the lower end of the sleeve 100. A compression spring 112 engages the upper tapered end 113 of the nipple 104 and the adjacent end of the pipe 62 to permit relative rotation of the pipe 62 with respect to the nipple 104. The annular collar 98, it will be noted, includes an upper beveled edge 114 which scalingly receives a cooperating annularly beveled shoulder 116 on the sleeve 100.

The nipple 104 includes a lower threaded end portion 118 which has a beveled terminal 120 which sealingly engages the lower flanged end 122 of the pipe 28 leading from outlet of the pump assembly 26, and is retained thereat by a clamp nut 124.

Secured to the rotatable pipe 62 by means of a collar 126 and set screw 128 is an annular disc 138 having radially extending abutment portions 132, 134 disposed in circumferentially spaced relation the same number of degrees required to swing the nozzle assembly 32 from centered relation over urn 12 to centered relation over urn 14 as shown by phantom lines in FIGURE 2.

In FIGURES 1 and 2, the switch 94, which is shown in detail in FIGS. 14 and 15, is closed when the abutment 134 depresses the actuating lever 136 thereof. It the pipe 62 is rotated counter clockwise the abutment 132 will contact the lever 136 after a predetermined amount of angular travel, i.e. when the nozzle assembly is over urn 14. When the abutrnents 132, 134 are not in contact with lever 136 the switch 94 will be open and the circuit to motor 84 will be open.

The switch 94 includes an insulated body 138 having a transverse pivot pin 140 upon which one end 142 of the lever 136 is journalled. The other end 144 of the lever is guided by a suitably slotted plate 146 secured on the end of body 138. The lead 88 is connected at 148 to the lever 136. The lever 136 includes a pivoted contact element 150 received in a bore 152 of the body, this contact element being engageable with a contact 154 connected to a lead 88' which is connected to the timer 92. Disposed in a recess 156 of the body 138 is a compression spring 158 engaging the underside of the lever tend ing to urge the contacts 150, 154 apart. The abutments 132, 134 when engaged in a recessed portion 160 of the lever 136, will overcome the compression spring 158 and cause the contacts 150, 154 to engage and thus the circuit to the field of motor 84 will be closed.

In FIGURES 2-7, it will be noted that the pump 96 is driven by the motor shaft 161 through a drive pulley 162 and belts 164 which engage a pulley 166 mounted on a shaft 168. The pump 96 comprises a cast housing 170 having an upwardly opening oil reservoir 172 closed at the top by a removable, suitably sealed plate 174. The housing 170 includes bosses 176, 178 extending into the oil reservoir and having co-axial bores 180, 182 respectively, which respectively receive suitable bushings 184, 186 of brass or the like which sealingly engage about and permit rotation of the shaft 168 which extends therethrough. The shaft 168 has circumposed thereabout a pressure sealing assembly comprising a washer 188 engaged by a pressure disk 198 which includes a recess portion 191 receiving a compression spring 192 therein,

the other end of the spring engaging a shoulder portion of an abutment block -194. The block 194 includes a recess 195 in which is received a ring bearing 196 which is retained in position by a snap ring 198. This assembly tends to draw the shaft 168 toward the right and affords proper impellor spacing.

The Wall 200 of the housing in which a portion of the bushing 184 is received includes a suitable seal 202, such as Teflon or the like, which will have the requisite lubricating and heat resisting qualities, and the shaft 168 terminates in a threaded end 204 in an impellor chamber 206 formed in the housing. Secured on the threaded end 204 of the shaft 168 is a bladed impellor 208 which will rotate clockwise as indicated by the direction arrow of FIGURE 7. The hub 209 of the impellor will be drawn into tight engagement on seal 202.

The housing 170 includes an annular collar 210 which opens into the impellor chamber 206 as clearly seen in FIGURE 3. A seal 212 engages the end of the collar 210 and receives thereon the flanged end 214 of a cooling head indicated generally at 216.

The cooling head 216 includes a substantially crescent shaped or arcuate cooling chamber 218; see FIGURES 3, 4, 6 and 8, and has an annular recess 220' surrounding the chamber 218. The annular recess receives therein a sealing gasket 222 and a sealing disk 224 overlies the recess and closes the chamber 218.

The housing 174 has a pair of forwardly extending, headed mounting bolts 226 which receive thereon a diametrically disposed clamp bar 228 which carries a threaded clamp screw 230 including a manually rotatable knob 232 at one end. The other end 234 of the screw is engageable in a recessed portion 236 of the sealing disc 224. When the clamp screw 230 is extended toward the disc 224, the heads 238 of the bolts 226 provide an abutment and the disc 224 is urged into sealed relation against the gasket 222 and seals ofl the cooling chamber 218 and urges the cooling head into sealed relation on the seal 212; see FIGURE 3. This clamp bar construction and operation is disclosed in detail in applicants above-mentioned U.S. Letters Patent 2,895,403 and further explanation in this regard does not appear to be necessary.

The housing 170 has formed thereon an inlet portion 240 to which the inlet line 24 is connected for the purpose of introducing substantially boiling water into the impellor chamber 206. The inlet portion 240 is offset relative to the impellor chamber 206, and terminates in a relatively wide throat 242, see FIGURE 6, which is in alignment with an annular intake chamber 244 in the cooling head 216, the chamber 244 including a tangentially ofiset, converging-inlet portion 246 including an entrance portion 248 aligning with portion 242 of inlet portion 248 of the housing. The inlet port 246 has an outlet portion 250 adjacent the lower peripheral wall of chamber 244 and causes a clockwise rotation of inlet, i.e. make-up water, in the same direction of rotation as the impellor 208. The chamber 244 communicates axially with the impellor chamber 206 and the impellor chamber has a tangentially disposed, upwardly converging outlet port 252 incorporated in an outlet portion 254 to which the line 28 is connected.

It will be observed that the aforementioned arrangement, i.e. common direction of rotation of the impellor and entrance of make-up water aflords the'most eflicient arrangement where the minimum load will be imposed on the pump parts and driving motor. The make-up water upon leaving chamber 18 is at almost 212 degrees F. and thus it is desirable to cool the make-up water not only to prevent the formation of vapor locks in the fluid lines, but a better brew of coffee is obtained if the coffee grounds are not subjected to boiling. The nozzle assembly 32 will disperse water to the grounds not only as a swirling spray to insure good contact with the grounds,

but with an accompanying swirling action of the grounds. The substantial elimination of vapor locks in the fluid lines will aid to maintain a uniform flow of make-up water and thus the timed interval of flow of make-up Water will always produce the same strength of brewed coffee, the essential variable being which orifice disc size is being used.

As previously mentioned, not only is it desirable to cool the make-up water below 212 degrees F., i.e. to about 208 degrees F., but due to the conductivity of the pump housing parts maintenance of the seals and bearings for the impellor shaft is critical.

The disc 224 includes a recess 256 on its underside receivable on an aligning pin 258 (FIG. 4) extending from the recess 220 of the cooling head 216. Extending through the disc 224 are threaded bores 260', 262, respectively alignable with and communicating with opposite ends 264, 266 of the arcuate cooling chamber 218 in the head 216. The arcuate chamber 218, it will be noted, encompasses a substantial circumferential extent of the impellor chamber 206 and is in close proximity to the impellor chamber and substantially surrounds the inlet chamber 244, see FIGURES 3 and 6.

The bore 260 is connected by a suitable connector 268 to a coolant line 270 which may be tap water regulated to attain the proper make-up water temperature in the impellor chamber. Coolant liquid (see FIG. 4) is directed into end 264 of the chamber 218 from line 270 and connector 268, and out of the end 266 of the chamber through a connector 272. The circulation of the coolant liquid in the chamber 218 results in a reduction of temperature of make-up water in the intake and impellor chambers 244, 206. The oil will be at a suitable level in reservoir 1172.

In order to maintain the bearing seals 184, 186 and oil reservoir 172 at the proper temperature, the housing has a pair of spaced apertures 274, 276 extending through the lower portion of wall 200' and communicating with the oil reservoir 172. A cooling coil indicated generally at 278 is disposed in the oil reservior "172 and includes a lower inlet leg 280 extending through aperture 274, the inlet leg 280 continuing in a forward U-shaped portion 282 extending over boss 176 and received in a groove in the upper surface of bushing 184. The portion 282 continues in a lower horizontal leg 284 disposed at one side of the lower portion of the oil reservoir and substantially the length thereof and continues in a rear U-shaped portion 286 which extends over the boss 178 and is received in an upper groove of the bushing 186. The coil continues from portion 286 in a second horizontal leg 288 at the lower portion of the reservoir which extends diagonally out of aperture 276 in the housing 1 70. The legs 280 and 238 which respectively extend through the apertures 274, 276 and have secured thereto suitable connectors 290, 292, respectively. The connector 292 is connected to a coolant outlet line 294 which will discharge into a suitable drain (not shown). The connector 290 is connected to a branch line 296 which communicates with the connector 272 in communication with the cooling chamber 218.

Thus it will be observed that not only is the make-up water cooled but the coolant fluid is circulated through the coil 278 to maintain the oil in reservoir 172 at a predetermined temperature, as well as the bushings 184, 186 through which the imlpellor shaft 168 extends.

Briefly in review, there has been disclosed a novel urn system including a novel beverage pump which will perrnit the production of a potable beverage by means of a single pass of make-up water through the use of a novel nozzle assemlby which includes inter-changeable orifice .rneans. Further, there is included means controlling operation of the novel pump especially adapted in a dual urn system, but also applicable in a single urn system when the discharge nozzle is not disposed in its proper discharge position over an urn. And still further, there has been disclosed means whereby a disposable porous groundbag may be used in the installation.

it will be obvious to those skilled in the art that various changes may be made without departing from the spirit of the invention and therefore the invention is not limited to what is shown and described but only as indicated by the appended claims.

What is claimed as new is as follows:

1. A system for brewing coffee or the like comprising an urn, a source of hot make-up water, a pump assembly connected to said source, said pump including an outlet, 21 grounds container overlying said urn for receiving make-up water therein to provide a potable brew, and a discharge nozzle superjacent to said grounds container and connected to said pump outlet for discharging make-up water downwardly into said grounds container, said discharge nozzle including a rounded chamber having means providing a metered bottom outlet orifice for affording a predetermined strength of brew during a single pass of said make-up water through said nozzle, said nozzle including an inlet discharging tangentially into said chamber from one side and above the plane of said orifice to provide a swirling spray discharge from said orifice against the grounds in said grounds container, so as to cause at least the upper portion of said grounds to move circularly and in intimate contact with said make-up water.

2. The structure of claim 1, said metered orifice providing means of said nozzle comprising a replaceable orifice-providing disc element which is interchangeable with other disc elements having orifices of different sizes for obtaining different strengths of brew, and each of said disc elements providing an inverted fustro-conical wall communicating with its discharge orifice.

3. The structure of claim 1, and a second urn and grounds container, a supply pipe between said pump and nozzle and having a vertically pivoted nozzle-carrying portion whereby said discharge nozzle is selectively positionable over said urns, and control means connected to said pump and operated by said nozzle-carrying pipe portion to permit operation of said pump only when the nozzle is overlying one of said urns.

4. The structure of claim 1, a supply pipe between said .pump and nozzle and having a vertically pivoted nozzlecarrying portion whereby said discharge nozzle is selectively positionable over said urn, and control means connected to said pump and operated by said nozzle-carrying pipe portion to permit operation of said pump only when said nozzle is overlying said urn.

5. The structure of claim 1, said pump including an impellor chamber, liquid cooling means for said impellor chamber and maintaining the make-up water below the boiling point thereof so as to avoid vapor pockets between the pump and nozzle and thus insure uniform flow of make-up water.

6. The structure of claim 5, said pump including a separate oil reservoir, an impellor shaft journaled in said reservoir, an impellor blade mounted on said shaft and disposed in said water cooled impellor chamber, and the liquid cooling means for said impellor chamber having a branch portion for cooling said oil reservoir and the shaft portions journaled therein.

7. The structure of claim 6, and a spring urged seal assembly wholly carried by said shaft between said oil reservoir and said impellor chamber, and an impellor chamber wall-provided bearing for said shaft toward which bearing an element of said seal assembly is actuated.

8. The structure of claim 5, said pump including a removable cooling head forming one side of said impellor chamber, said cooling head including a cooling chamber .as a part of said cooling means and communicating with a source of coolant, and said head-provided cooling chamber substantialiy surrounding said impellor chamber.

9. The structure of claim 8, said cooling head including a tangential port offset from said impellor chamber and communicating axially therewith, said impellor chamber including a tangential discharge port, said inlet and discharge ports of said impellor chamber providing a centrifugal inlet and outlet for make-up water around said impellor chamber.

10. The method of brewing coffee of maximum strength in a single passage of make-up water through a quantity of ground cof ee, and wherein the make-up water is propelled by a rotary type pump having a bearing-supported shaft, the make-up water at its source being close to or at the boiling point; said method comprising the use of a circulating coolant for reducing the temperature of the make-up water to just below the boiling point at the site of the pump, so as to avoid vapor lock formation in the make-up water line and at the same time circulating said coolant adjacent the pump shaft hearings to prevent overheating of the latter, discharging the thus near boiling make-up water in a swirling spray, against a quantity of circularly confined ground coffee, whereby to set up some swirling action in said coffee, and collecting the thus produced strong coffee in a subjacent container.

11. The method of brewing coffee of maximum strength in a single passage of pump-propelled make-up water through a quantity of ground coffee, and wherein the make-up water at its source is close to or at the boiling point; said method comprising the use of a circulating coolant for reducing the temperature of the make-up water to just below the boiling point at the site of the pump, downwardly discharging the thus near boiling make-up water in a swirling spray, against a quantity of fixedly supported and circularly confined ground coffee, whereby to set up some swirling action in said coffee, and collecting the thus produced strong coffee in a subjacent container.

12. For use in a coffee brewing system or the like, a pump comprising a casing providing a lubricant chamber, having an end wall, an adjacent impellor chamber and a partition separating said chambers; said impellor chamber having a fluid inlet and a fluid outlet and being open at the end opposite said partition, a removable and par tially hollow closure for the open end of said impellor chamber and securing means for said closure; an impellor in said impellor chamber, a supporting shaft for said impellor, bearings for said shaft and carried by said partition and the end wall of said lubricant chamber; and a coolant circuit including said partially hollow impellor chamber closure and providing a coil in said lubricant chamber.

13. The structure of claim 12, and said shaft bearings having portions extending into said lubricant chamber and providing seating recesses, and portions of said coolant coil engaged in said recesses whereby to positively anchor said coil in the lubricant chamber while cooling said bearings.

14. The structure of claim 12, and the hollow portion of said impellor chamber closure having a recess opening toward said impellor chamber and providing an extension of the latter.

15. In a coffee brewing urn system providing an upstanding, vertically journalled and generally inverted L- form pump fed make-up water supply pipe portion pro viding a discharge nozzle at the free end portion of its head end, there being an electric motor drive for said pump and an energizing circuit for said motor, said pipe being swingable to and from a position to dispose the nozzle over an urn-provided coffee ground container; the improvement which comprises an urn-supported and noranally open cut out switch for said motor circuit, and a camform switch closing member on the upstanding part of said pipe portion and engaging and closing said switch only when the discharge nozzle is over the coffee grounds container.

16. In a system for brewing coffee including a makeup water source wherein the water temperature is maintained at or above the boiling point, said system also including a pump assembly including an impellor chamber and an adjacent oil reservoir, there being an impeller in said chamber having a shaft extending through said lubricant chamber and supported by bearings therein, said impel'lor chamber having an inlet and an outlet, the inlet communicating with said make-up water chamber and the outlet piped to discharge into a coffee grounds container; the combination of a cooling fluid circuit having portions in close adjacency to both said impellor chamber and oil reservoir, whereby to prevent overheating of the impeller shaft bearings and also to so reduce the water temperature in said impeller chamber as to prevent a steam created vapor lock therein.

17. The combination set forth in claim 16, and said pump assembly including a removable cooling head defining a part of said impellor chamber, and said cooling head providing a cooling chamber Which is incorporated in said cooling fluid circuit.

18. The combination set forth in claim 16, and a coil incorporated in said cooling circuit and located in said lubricant chamber, and a portion of said coil engaging at least one of said impellor shaft bearings.

19. In a commercial coffee maker comprising a makeup water supply pipe having a discharge end, an open topped ground coflee container below said pipe discharge end to receive hot make-up water from the latter under pressure; the combination of a nozzle comprising a hollow closed topped body disposed above said coffee container and providing a generally circular chamber, an inlet portion provided by said body at one side and connected to the discharge end of said supply pipe, said nozzle inlet substantially tangentially communicating with said chamber, a clamp ring removably secured to said body, an interchangeable chamber bottom-providing disc element providing a downwardly discharging fluid outlet orifice which is concentric with said chamber and also an inverted substantially frustro-conical wall communicating with said orifice, and the orifice being of a size to discharge a swirling spray of suflicient force to swirlingly actuate the ground coffee in said container.

References Cited in the file of this patent UNITED STATES PATENTS 494,206 Jones Mar. 28, 1893 501,178 Bourdil July 11, 1893 956,332 Fuller Apr. 26, 1910 1,226,005 Rathman May 15, 1917 1,251,410 Norton Dec. 25, 1917 1,289,337 Wil-fley Dec. 31, 1918 1,650,128 Hubband Nov. 22, 1927 2,061,119 Voigt Nov. 17, 1936 2,224,409 Schleyer Dec. 10, 1940 2,368,962 Blom Feb. 6, 1945 2,493,932 Swanson Jan. 10, 1950 2,687,096 Armacost Aug. 24, 1954 2,706,444 Chaplik Apr. 19, 1955 2,741,991 Disbrow Apr. 17, 1956 2,748,689 Rotman June S, 1956 2,827,845 Richeson Mar. 25, 1958 2,895,403 Matty July 21, 1959 FOREIGN PATENTS 117,668 Sweden Dec. 19, 1946 

10. THE METHOD OF BREWING COFFEE OF MAXIMUM STRENGTH IN A SINGLE PASSAGE OF MAKE-UP WATER THROUGH A QUANTITY OF GROUND COFFEE, AND WHEREIN THE MAKE-UP WATER IS PROPELLED BY A ROTARY TYPE PUMP HAVING A BEARING-SUPPORTED SHAFT, THE MAKE-UP WATER AT ITS SOURCE BEING CLOSE TO OR AT THE BOILING POINT; SAID METHOD COMPRISING THE USE OF A CIRCULATING COOLANT FOR REDUCING THE TEMPERATURE OF THE MAKE-UP WATER TO JUST BELOW THE BOILING POINT AT THE SITE OF THE PUMP, SO AS TO AVOID VAPOR LOCK FORMATION IN THE MAKE-UP WATER LINE AND AT THE SAME TIME CIR- 